Portable water still



Sept l2, '1944- v l.. M. BEcKwlTH POTABLE WATER STILL Filed April 1, 1942 Patented 'septia 1944 2,357,869 PORTABLE. WATER STILL Leo M. Beckwith, Brookline, Mass.

Application April 1, 1942, Serial No. 437,247

13 claims. f (o1. 2oz-185) This invention pertains to stills for use in converting sea water into drinking water, and relates Vmore particularly to a portable still for emergency use, for instance for use in the lifebo-ats of aircraft. Y l

For such purposes a still must be very compact; of small external dimensions and light in weight, but at the same time capable of producing a substantial'quantity of drinking water by the combustion of a minimum amount of fuel; it should be so devised as to operate satisfactorily with a solid non-explosive fuel; capable of operation in the tropics as well as in cooler climates; and it ject to corrosion or deterioration whenl exposed to the weather, and to sea water.

The principal object of the present invention is to provide a portable still having Aall. of the above desirable characteristics embodied inapparatus of practical construction ,and which may be produced on a commercial scale at areasonable cost. Other and further objects and advantages of the invention will be pointed out in the following more detailed description and by reference to the accompanying drawing vwherein Fig. 1 is a diagrammatic elevation showing the still with its several parts arranged for operation;

Fig. 2l is a View, to larger scale, showing the boiler and burner units of the device in vertical section, but showing thecondenser and flexible tubing in elevation (certain parts being broken away); f

Fig. 3 is -a fragmentary section on the same plane as Fig. 2, but to larger scale, illustrating certain details; land f aluminum anodized to make it resistant to corrosion will be used for lmost of the metallic parts of the apparatus. The burner unit 3Min the specific embodiment herein disclosed, comprises the cylindrical openended shell 'I (Fig. 2). having within its lower. Y

part, but spaced from its lower end, a supporting shelf 8 which may be held in place in any desired manner but'with provision for the pasasge of air upwardly from the spacebelow -the shelf to that above it. Above the shelf 8 there is arranged an I annular septum 9 which completely divides the must be rugged and durable and not readily sub- Y Y Y movable platform Fig., 4 is a similar view illustrating other details.

Referring to the drawing (Fig. l) the numeral I designates the portable still'of the present invention with its. parts arranged in the position which they occupy when thel still is in operation. This still comprises the boilerV unit 2 having the removable cover` 2a, the burner unit 3,'the condenser 4, the flexible tube 5 connecting the boiler unit with the condenser, and the flexible vent tube 6. l

It is to be understood that the severalV parts of the stm win be made of material which is' not I readily corroded when exposed to the weather or to sea water and which is not'injuriously affected by the products of combustion of the solid fuel employed, and that they parts will be made as light as possible commensurate with the requisite durability and strength. Preferably sheet lower and upper parts ofthe space within the shell except for the central opening in the'sepl tum. The space VI0 betweenthe shelf 8 and the septum 9 constitutes a combustion compartment and the shell is furnished with a fuel admission opening leadingA into this compartment; and

which is normally closed by a door II.v .An'airV admission opening I2 permits the free entrance of air into the space below the shelf 8.

The shelf 8 supports acylindrical positioning ring I3 within which isarranged the verticallyV I4 resilientlyV supportedk by I'I of the receptacle is usually beaded or rounded."

The height of the compartment I0 is such that when the receptacle I6 is seated on the platform I4, where it is held in place'by` the ring I3, its

upper edge is heldin close engagement with the under surface of the septum 'by the upward urge of the springs I5; Y

- An open-topped sleeve I8 of perforated metal or other suitable non-combustiblematerial is arranged above the septum 9, coaxially withthe opening in the septum, and is secured to the sepf tum in any desired mannerl VAs here indicated it is integral with the septum butv it may be a sepa- K .rate element if preferred. This sleeve I8 extends up nearly to the top of the burner unitfand within itis arranged the hollow-cylindrical'fperforated ame spreader I9, closed at-top and bottomY and supported by the sleeve I8 bylrneansl ofrsuitable brackets 20, As here illustrated theseH brackets are tubular so as tofprovide communication betweenV the interior ofY the hollow flamelspreader and the space outside the sleeveISL space The flame spreader I9 is of such external diameter as to provide an annular flue 2l between it and the sleeve lilthis flue providing for the upward travel of the products of combustion.

VSurrounding the sleeve I8 is a guard cylinder 22 flue z2a into intimate Contact with the upwardiy moving stream of hot gases and to contract said Stream as it emerges from the top of the flue 2l, thereby to concentrate thek heat of said gases against the bottom of thef'boiler.

That portion of the shell 1 which surrounds the guard cylinder 22 is preferably provided with a lining sleeve 24 spaced from theV inner wall of the shell to provideV an annular chamber for the f reception of insulating material 25,such for example as compressed glass wool; VPreferably this n Ashould be *1/4 inch or more in-radial thickness. Y Y

The upper portion of the'shell V'l is turned outwardly as shown at 26 (Fig. 3) and then upwardl7 Yat 2.1 and the upper portion of the lining` 24 is turned outwardly at 28 so asV to overlapthe part 26, thereby providing the recess Re.. (Fig. 3) for the Vreception of the lower edge of the boiler unit -2.

The lower end of the shell 1 is preferably nor-r ly than the lower wallso as to provide between them a space 43, for example two inches or more in depth, within which ispacked suitable insulation, for example glass wool. The walls 40 and 4| are permanently united at their outer edges as indicated at 42, and the margin of the lower wall 40 is preferably bent upwardly as indicated at 40.a (Fig.` Ll) toprovide a deep annularfrecess or channel containing resilient packing material 405? and which receives the rim bead 38'of the boiler.

The cover 2a is provided at suitable intervals about its circumference with outstanding brackets 44- to which are pivotally secured clamping bolts 45 which normally project'down through j Y open-ended slots in brackets 46 fixed to the shell 32 and Whichcarry wing nuts 41 at their lower ends by means of which the cover may be drawn' down toward the boiler solas to form a leak-tight joint between them. Brackets 48, .similar to j' jecting from the upper part of the shell 'IA and n which carry wing nuts 5Il at Itheir lower endsby means of which the boiler 'unit may be releasably mally closed bya grid 2,9., This grid is provided., l

with a cylindrical portion 30 which isfdesigned to slide into the lower end ofthe shell A'Fwith a tight f fit so as-to be retained tl'rerein fri'ctionally, although removable therefrom' at will. The grid also has the outturned flange 3lV on which the lower edge of thershell 1 normally rests,; said .fange 37| forming a foot or base for the support of the burner unit. V

The boiler unit 2 comprisesrthe she1l`732V open l Y atv top andbottom andof suchpdiameter that its lower end may iitlsnugly within the recess R of the burner unit.\ This shell '.32 is preferably provided witha lining cylinder 33 extending from its n lower end to a point near but spaced from its upper end, the lining cylinder 33 being of such-diameter as tol provide a space between it and the shell Y 32 for the reception of insulation such as compressed glass wool, the thickness of the insulation preferably being 1A; inch or more. Y sulation. the shell32 is preferably provided witha plurality of. vent'openings .35 through which the products oit-,combustion may escape. to the atmosphere.l

Above the in- Y within the boiler unit is arranged the tonerV 36. Y As here illustrated this boiler is a unitary piece of sheet metal, suitably shaped fby pressure or the like andpreferably ofra size such that it will hold six quarts or more of water. 'The upper Y portion of this boiler is shaped to provide theoutwardly divergent; skirt 31-'which1is' provided at *itsY extreme upper edge with a bead 38 which, if Adesired; may" be Yreinforced yby. a stiff 'wire' ring.,

This beadis designed torestupon the upper edge of theshell32 and therebyto support the boiler The cover 2a of the boiler preferably comprises the lower Wall 40 and theupper. wall 4 l said walls V Y being of sheet material and both being domed up- Y When'the condenser is in use, and preferably to toV ' up through vkthe tube 6 andinto the boat where secured to the burner unit.

A pipe or conduit 52 passes through the cover 2a from the interior to theexterior hereof, the inner end of the pipe being provided with packing and locking means 53 thereby to prevent escape of steam'betweenrthe pipe and the cover. At its outer end the pipe 52-is provided with means for f receptacle of suitable rigid material, preferablyv sheet metal, of a size such that it may be nested within the boiler, as illustrated in dotted lines at 4a (Fig. 2') and of a capacityof two quarts or` more. This condenser 4 is provided with an out- Y wardlyprojecting nipple 55 having provision for removablysecuring to it a union 56' at the lower end of the ,flexible steam`tubing The Ycondenser is also provided with a lprojecting nippler55 to which the lower yend of the Vflexible vent 6 may be secured. This vent permits the es#` cape of air or gas which may be released fromrthe water during distillation. Preferablyrthe Vcondenser 4 is provided with a ring 58 for use in at- Vtaching thecondenser to some' appliance, for example a boat oar, by meansof which th'etcondenser may be thrustibelow Vthe surface of the sea and held there during the distiljling operation.Y The length'of the flexible steamrtube 5 will be such as to permit such location of the condenser, n while at theisame time theburnerand boiler Y. units are supported in upright positionwithin the The venttube 6 is also of such length'asV boat.' to' reach at least above the surface cf the sea reach tothe interiorV of the boat, although it is contemplated that the upper end of thisvent tube 6 may be supported by a float if preferred. It is 'V evident that if the Water be permitted to accumulate in the vessel 4until the latter is full, the continued operation of thedev-icewill generate steam pressurersuiicient .to forcejsome of the waterV vice, a bail 58 is attachedtorears.'59,;securedlto L i boiler unit 2.V Y I" the upper part of the wardly, the upper 'wall4i being domed more deep- When the device is not in use the condenser 4 and the exible tubes 5 and 6 are housed within the boiler unit, thus providing a very compact and readily portable device. When the still is` to be used, the condenser 4 is removed from the boiler, the tubes 5 and 6 are connected and the condenser is placed overboard and held immersed in the sea. A quantity of sea water is placed in the boiler 36 and the cover 2a is clamped in position. A receptacle I6 containing solid fuel being provided, the fuel is ignited and the receptacle is placed on the platform 4 within the compartment l0, and the door Il is closed; The burning of the fuel produces a flow of hot gases up through the flue 2|, and this stream of hot gases, impinging upon the under side of the boiler and passing up along the sides of the latter quickly raises the sea Water in the boiler to boiling temperature. To facilitate the transfer of heat from these hot gases to the contents of the boiler, the under portion of the boiler may be provided with heat transferring fins 60 if desired. If desired, the outer edges of these iins may be united, integrally or otherwise, with an annulus, coaxial with the boiler, and operative both to reinforce the fins and to reflect the hot gases back against the boiler. rHowever, such annulus forms no necessary element of the present invention, Vand accordingly is not illustrated. A flint lighter, not

shown, is desirably attached to the outside of the apparatus.

The steam which is evolved from the boiling sea water passes out through the pipe 52 and down through the steam tube 5 into the condenser 4 Where it is condensed by the surrounding cooler sea water. A device such as that herein disclosed is readily capable of producing as much as three pounds of potable water per hour measured from the time of ignition of the fuel--starting with sea water having a salinity of at least 4% when the cooling water available is at a temperature not exceeding 90 F. The salt in the distilled water resulting from this operation will not exceed six grains per gallon for the first pint of by the use of a sufficiently long tube 5, coupled directly to or itself constituting the vent pipe B,

adequate condensation could be insured even though the vessel 4 were injured or lost.

When not in use as a still, the boiler unit may be removed from the burner unit, and the -grid 29 may be removed and placed on top of the burner unit and employed as a cooking surface. While a fuel container and fuel such as above referred to are preferable,`other types of fuel may be burned in the compartment l0, if desirable or necessary. However, the fuel selected should be safe to use; preferably solid; explosion and leakproof; it should not melt as it burns; and should have a high B. t. u. value.

While one desirable embodiment of the invention has herein been disclosed by way of example, it is to be understood that the invention is not necessarily limited to this precise embodiment but is to be regarded as broadly inclusive of any and all equivalent constructions falling within the scope of the appended claims.

I claim:

1. A portable still comprising a burner unit, a boiler unit, a condenser, a conduit connecting the interior of the boiler unit with the condenser when the still is in use, said units being independent and separable, means releasably uniting the burner and boiler units, the burner unit having therein provision for removably supporting a lcontainer for solid fuel and the boiler unit including an outer shell having a covered boiler removably supported therein, the boiler and condenser being of such shape and dimensions that the condenser may be housed within the boiler for storage.

' 2. A portable still comprising a condenser and a boiler unit, the latter including an insulating substantially rigid shell and a boiler removably supported upon the upper edge of the shell, the boiler having a steam-tight removable cover, and a conduit connecting the interior or the boiler unit with the condenser when the still is in use the boiler and condenser being so shaped and dimensioned as to permit storage of the condenser within the boiler when the device is not in use.

3. A portable still of the kind in which aboiler unit is supported by and is removably united to a burner unit, and wherein a condenser is so connected to the boiler unit as to receive steam evolved in the boiler unit, the burner unit comprising a substantially cylindrical outer shell open at its lower end, means operative to support a fuel container within the shell, and a grid normally closing the lower end of the shell, the grid having a flange portion upon which the lower edge of the shell normally rests and a portion which ts frictionally Within the lower end of the shell, the grid being designed for application to the upper end of the shell upon removal of the boiler unit.

4. A portable still of the kind in which a boiler unit is supported by and is removably unitedv to a burner unit, and wherein a condenser is so connected to the boiler unit as to receive steam evolved in the boiler unit, the boiler unit comprising a substantially cylindrical shell, the upper portion only of the boiler engaging the shell, the boiler proper-depending from its upper portion and being spaced from the inner surface of the shell, the latter having a cylindrical lining in that portion which surrounds the boiler, and insulating means between the lining and shell, the latter having vent openings in its upper part through which gaseous products of combustion rising along .the sides of the boiler may escape to the at-y mosphere.

5. A portable still of the kind in which a boiler unit is supported by and is removably united to a burner unit, the boiler unit comprising a substantially cylindrical shell, a removable cover for the boiler, means providing a steam-tight joint between the cover and boiler, a conduit leading from the interior to the exterior of the cover, a condenser of a shape and size such that, when not in use, it may be nested within the covered boiler, and means connecting the condenser and said conduit thereby to permit steam evolved in the boiler to pass to the condenser.

6. A portable still of the kind in which a boiler unit is supported by and is removably united to a burner unit, the boiler unit comprising a substantially cylindrical shell, a removable steam-tight cover for the boiler, a condenser consisting of a fluid-tight receptable of a size and shape such 7. A portable still of the kind in which a boiler Vunit is supported by and is removablyunited to a burner unit, the boiler unit comprising a substantially cylindrical shell, a removable steamtight Vcover for the boiler, a condenser consisting of a iiuid-tight receptacle of a size and shape such that it may be nested within `the covered boiler when not in use, said receptaclehaving a pair of outwardly directed nipples each designed for the reception of the end of a flexible tube, the cover having a conduit leading from its inner to itsouterside, said conduit having provision for attaching thereto one Vend of one Vof said tubes, the receptacle being provided with connecting means whereby an implement may be attached to it for holding it wholly submerged in sea water- Y 8. A portable still for use in a lifeboat or the like, said still comprising a burner unit, a boiler unit and condensing means arranged Yto receive steam from the boiler unit and designed to be immersed in sea water alongside the lifeboat, the boiler and burner units being independent and separable, releasable clamping means normally uniting the boiler and burner units with the boiler unit resting upon the burner unit, the burner unit having therein provisionfor removably supporting a container for solid fuel, and the boiler unit including an outer shell having a covered boiler receptacle removably supported therein, the boiler and condensing 4means being of such shape and dimensions that the condensing means may be housed within the boiler for storage.

9. A portable still as set forth in claim 8, further characterized in that the boiler and burner units are of substantially cylindrical shape and of substantially the same diameter and disposed in coaxial relation, each of said units having a double walled shell with insulation interposed between its walls.

10. A portable still for use in a lifeboat and the like, as set forth in claim 8, further characterized in that the outer shell of the boiler unit is open at both ends and has vent openings at its upper part, the boiler receptacle being disposed` with-V in said shell and having an upwardly flaring skirt portion designed to engage and to be supported by the upper edge of the shell, a removable cover for the boiler receptacle, and means operative to clamp the cover tightly to the skirt portion of the receptacle. c

11, A portable still for use in a lifeboat or,l the like as set forth'in claim 8, further characterized in that the boiler receptacle has an upwardly fiaring skirt portion provided at its edge with a bead designed to rest upon the upper edge of the shell of the boiler unit, a removable cover, packing interposed between the cover and said bead, andY clamping means operative to draw the cover toward the bead thereby to compress the packing.

12. A portable still for use in a lifeboat, as set forth in claim 8, further characterized in hav-V ing means for suspending ,the boiler receptacle from its upper edge within the upper part ofthe shell of the boiler unit,rthe boiler receptacle having a steam-tight cover, and heat conducting fins forth in claim 8, further characterized in that the f boiler receptacle has a removable domed cover,

' the cover including upper and lower wallsunited Y end of said conduit.

LEO M. BECKWITH. 

